qcacmn: Assign an enum value to an undefined dfs region

Assign an enum value to an undefined dfs region.

Change-Id: Ia078b3853db38e54d2340e07f7bbd2b636e16bc2
CRs-Fixed: 2274203

umac/regulatory/core/src/reg_db.h

@@ -64,7 +64,7 @@ enum dfs_reg {
 	DFS_MKK_REG = 3,
 	DFS_CN_REG = 4,
 	DFS_KR_REG = 5,
-	DFS_UNDEF_REG
+	DFS_UNDEF_REG = 0xFFFF,
 };
 
 /**